An ultrasound diagnosis apparatus transmits ultrasound waves to a subject by an ultrasound probe including a plurality of ultrasound transducers. The ultrasound diagnosis apparatus generates tomographic image data, three-dimensional image data, and the like of the inside of the subject based on reflected waves (ultrasound echo) from the subject.
The ultrasound diagnosis apparatus may be configured such that the ultrasound transducers are driven by a voltage induced in the secondary winding by a voltage applied when a power source is connected to the primary winding of a transformer. With this configuration, by switching the direction of current applied to the primary winding, the polarity of a pulse induced in the secondary winding can be reversed. The ultrasound diagnosis apparatus configured like this outputs a positive voltage signal, a negative voltage signal corresponding to the positive voltage signal with polarity reversed, and three-level voltage signals of the zero voltage signal to the ultrasound transducers as transmission signals. Besides, the ultrasound diagnosis apparatus having such a configuration variously controls the width of the pulse induced in the secondary winding to control the ultrasound frequency characteristics.
There is Besides known the ultrasound diagnosis apparatus configured to variously control the voltage level of voltage signals using a digital-to-analog converter (DAC) and a linear amplifier to thereby control the ultrasound frequency characteristics.
However, the various control of the pulse width requires a higher clock frequency. Moreover, due to the effect of the rise characteristics of the transmission signals, it is difficult to output transmission signals of wide pulse width and those of narrow pulse width with equal amplitude to the ultrasound transducers.
In addition, the use of DAC and a linear amplifier requires a large transmitter circuit. This necessitates a high cost and large power consumption.